Artificial limb



March 28, 1939. c. H DAVIES ARTIFICIAL LIME Filed May 4,

1936 2 Sheets-Sheet 1 ARTIFICIAL LIME Filed y 4, 1935 2 Sheets-Sh 2 s apertures which taper toward the Patented Mar. 28, 1939 UNITED STATES PATENT orrlce ARTIFICIAL Lnm Charles 1!. Davies, Philadelphia, Pa. Application my 4, 1935, Serial No. 19,89!

5 Claims.

description of a specific exempliflcation, such a description will be given with reference to the accompanying drawings which show a practical embodiment.

In the drawings: a

Figure 1 is a side elevation of an artificial limbembodying the present invention.-

Figure 2 is a vertical section of the limb of Figure l.

Figure 3 is a section substantially on line 1-3 of Figure l.

Figure 4 is a rear elevation of Figure 1.

Figure 5 is a front elevation of a bracket utiof the knee joint 2o lized in the knee joint.

Figure 6 is a section substantially on line H of Figure 1. v y

Figure 7 is a bottom plan view of the lower end of the shin se'ction,-and

Figure 8 is a plan view the foot.

Referring to the drawings, reference numeral ll designates the thigh portion of an artificial limb. reference numeral ii the shin portion, and so referencenumeral II the foot portion. The thigh and shin portions are of hollow,

of the heel portion of having a closed lower end as here shown,

ures 2 and 3;

r The top edge of the shin portion is substantially flat as to its forward portions as at it, Figure 3, its rear portion dropping substantially as at ll. The upper margins of the shin portion are circumferentially rimmed inwardly by a welded bracket ii, the bracket being preferably an integral unit andcomprising a forward band It and a rearward downwardly extending band ll whose top edges are flush with edges and II respectively. Intermediate edges II and II the shin is providedwith arcuate recesses iland II and bands it and II have at their iunctures upstanding ears 2| and ii outwardly enlarged to provide'bosses which are, received in recesses II and is. The outer faces of the bosses are substantially flush with the outer surfaces of the shin portion and will substantially merge with the latter during the welding operation so that a flush exterior is provided.

Bars "and II are provided with hexag nal right, Figure 3,

whereby their reliability is enhanced and preferably metal, construction, the spun and formed thigh section the aperture in ear 20 being larger than that in ear 2i. These apertures receive the tapered hexagonal throat and tip portions 23 and 24 of a round bolt 25 which is relieved medially to. provide a hexagonal section 21,- and its tip is provided with a tapped bore in which is threaded a retaining screw 28. The original clearances are such, with the hexagonal portions of the bolt wedged in the receiving aper- 20. Bolt 25 has a head 5 tures, that upon the occurrence of wear the bolt 10 may be axially displaced bytightening screw 28 to re-engage it tightly 'in the apertures, Due to the non-round shape of the apertures, bolt 2! is rigidly held against rotation relative to the shin portion.

The side walls of the lower end of the thigh portion it are inwardlybulged and apertured to receive nipples 29 and 30 which have outer end flanges received in the inwardly offset margins of the apertures and abutting the same. apertures are rimmed by inwardly projecting annular flanges, Figure 3, to provide ample bearing surfaces for the nipples. The inwardly extending externally threaded portions of the nip- Theao pies have screwed thereon retaining rings 8! and as 32, which are engaged around the annular flanges and have dished radial flanges engaging around I the annular shoulders, provided by the bulged side walls, the margins of the side wall apertures being clamped between the nipples and rings.

Nipple is has an integral annuhr flange II against which abuts an inner ball race 84, the outer race ll being of nipple Nipple ll has a similar andcarries the inner and outer races The inner races 34 and I1 bear on-pivot bolt 1!. Non-metallic washers are preferably interposed between the ball bearing assemblies and the hearing ears 2. and II.

The outer portions of the bearing and iii are substantially flush with the sub of the thigh portion and are walls in :1 and a.

carriejrsll position not only through engagement with m I annularflanges of theside wall apertures clamped bolt II is a split brake parts SI and 40. The part notch, shaped to fit agains hexagon 20, the two opposite at being continued outwardly to the split 'aplaneremotefromtheboituis.

I is in effect the hub. Strap 48 is portion 40 has lug portions 4! and 42 projecting into the notch of portion 39 and engaging the other three sides of the hexagon 26. The drum parts are clamped securely against the pivot bolt by means of screws 43 and 44 whose heads are inset in part 40 below the periphery thereof. A pair of arms 45 and 46, here shown as integral with part 39, project substantially radially from the latter and at their outer ends carry a roller 41 under which is passed, between the arms, a control strap or suspender 49. Arms 45 and 46 constitute a knee lever of which drum 39, 40

passed out through openings in the thigh portion in in the well known manner and may have its ends secured to a belt, the top forward portion of the strap being constituted by an elastic band.

A band 49 has one end bolted or riveted to the rear wall of the thigh portion and is looped around hub 39, 40 between the lever arms. The other end of the band has secured thereto a threaded stem 50 which is passed through an opening in the rear wall of the thigh portion to receive a wing-nut Band 49 has av friction liner 52 engaging the drum.

By suitably adjusting nut 5| the band tension may be altered to modify the knee action as desired by the wearerga principal purpose of the braking arrangement being to control the forward movement of the shin portion, abrupt movement being'prevented so that a more natural action the pivot bolt by structure forthe shin portion and Bolt 25, by reason of its.

is afforded.

knee action may also be readily modified by anging the angular position of the knee lever c and this may be accomplished without removing I merely loosening screws 43 and, the top portion of the brake band being temporarily pulled in out of the way, and swinging the lever relative to the pivot bolt. The screws have their major portions threaded into the drum portion 39 and maybe threaded out sufficiently to permit swinging of the lever without their entire removal. Since the heads of the screws are faced upwardly, they are accessible.

from the top of the thigh portion. Adjustment of the knee lever may, of course, also be effected by withdrawing the pivot bolt 25 sumciently to enable it 'to be turned in its receiving apertures and then re-inserting it in a new position.

The lower rear extremity of the thigh portion is inwardly off-set at 53 'and in the oif-set is fixed apad 54 of compressible material, the off-set and pad extending substantially from side to sideof the thigh portion. Pad54 is positioned .to cooperate as an abutment-with the rear band I! ofbracket i5 substantially through-. out the rear portion .of the latter to limit forward movement -oflthe shin portion relative to the thigh portion. Due to this elongated contact zone evensevere abutment shocks have no distortive effect on eitheriofthe limb portions, any'sueh effect on. the shin portion being prevented. in the first'instance by'the-intervention of they relatively rigid band I! of the bracket. The bracket J5 thus not only serves; to finish and reinforce the upper edge oi the shin portion and to'carry the'pivo't'bolt; but it also serves as anabutment member to limit relative movement portions.- "It provides an extremely rigid top servesto distribute thrustthereto.

hexagonal end portions engaged in mating openingsinthe bracket, is securely held against. rotati n; relative to the shin portion and this is 01' grat 'importance 'inasmuch as the action of the through this bolt. completed by the secured clamping of the lever of the limb suspender and also of the brake is transmitted This rigid construction is and drum to the hexagonal medial portion of the bolt. The bracket 15 is preferably an aluminum forging for the sake of lightness and strength.

The rear of the thigh portion at theknee is flattened as indicated at 55 and upwardly curvedly merged into a curved junction line 56 with the surmounting wall portion. The line 56 is so chosen that upon extreme relative bending of the limb portions it will abut substantially throughout, the rear reinforced edge of the shin portion. Due to this elongated zone of contact and also due to the thickened upper rear edge of the shin portion, local crushing effects on the rear wall of the thigh portion are avoided. As may be seen from Figure 2 when the thigh portion has been bent relative to the shin portion to bring about abutment between the upper edge of band portion I1 and the thigh portion at 56, the latter has moved through an angle substantially greater than a right angle relative to the shin portion. This is important as enabling the wearer to kneel without a tendency to be thrown forwardly off balance.

The lower edges of the shin member are in substantially the same plane except that each side wall has an arcuate downward extension, these being designated as 51 and 58. In the heel portion is set an inverted cup-like member 59 which has side and rear flanges welded to the walls of the shin portion. Member 59 is to the rear of the extensions 51 and 58. A plate 60 is welded to the front lower edges of the shin portion, and a heavier plate 6| underlies the lower forward edges of the shin portion and is secured to plate 56. I

The ears 5! and 58 are inwardly oiT-set as are also the side wall portions thereabove, depressions 62 and 63 being thus formed. The ears have outwardly projecting flanges, Figures 6 and 7, which form lower bounding wallsfor the depressions. Each of the depressions has Irontwardly and rearwardly extending branches as at 62a and 62?), Figure 1, and inserts 64 and 65 are received in the respective recesses, each being shaped as shown in Figure 1.- In this figure the insert 64 is shown, the insert having arms 64a and 64b extending into the branches 62a and 62b, the lower portions of the inserts overlying cars 51 and 56 and abutting the flanges .of the latter. The inserts are welded in position and carry in suitable openings ball bearing assemblies 66 and 61 which may be screwed or pressed into position, the inner races receiving the reduced ends of a pivot bolt 68 into the ends oi' iwhich-are threaded screws 69 and which engage washers overlying the outer ends of the inner races of the ball bearing assemblies. The latter are assembled with'theinserts after the ends of bolts 68 have been positioned in the insert openings.

While I have stated that inserts 64 and 65 are weldedin place, it will be understood that this is the practice preferred by me and that rivetting or-other suitable assembly practice mayQbe used if desired. bracket l5 and other parts.

The central portion of bolt 68 is engaged in the eye of a bolt H whose threaded stem is passed through the foot and engaged by a nut .12. foot supports a bolster 13 which has two channel portions 14 and of arcuatecross section; in which the end portions of bolt 68 are seated, a

The-

vIlti non-metallic cushion 16 being interposed between the bolt and the channel portions. Bolt H extends through the slot 11 which separates the channel portions 14 and 15. The latter have fixed in their bottom walls upwardly projecting pins 18 and 19 which engage with a close fit in sockets in the underside of the pivot bolt so that the latter is securely held against rotation and axial displacement. Bolt 'II is secured to bolt 68 through a set screw 80, but since this screw may come loose and since moreover the stem may wear away and enlarge the bore in the foot through which it is passed, I have provided the pin and socket connection which insures that the pivot bolt will be held absolutely fixed, the cradle, it will be understood, being rigidly fixed in the foot portion. The ankle connection is completed by an elongated rubber pedestal 8| interposed between the heel of the foot and. the shin portion with its upper end seating in cup 59 and a rubber pad 82 interposed between the foot portion and plate 6|. The described ankle assembly is very resistant to torsional stresses, the lower end of the shin portion being reinforced in this respect by the frontwardly and rearwardly extending arms of the inserts.

It will be observed that the bracket l5 positions the pivot bolt 25 nearer the rearward than the forward portion of the upper edge of the shin portion and that the pivoting axis of the thigh portion is similarly rearwardly positioned. This is important in that with this relation of parts the weight of the wearer is predominantly forward of the pivoting axis in the straightened relation of the limb portions so that the lower rear surface of the thigh portion tends to maintain its abutting relation with the rear band portion l1. Accidental bucking forward of the knee is thus prevented.

Since changes in form and arrangement may be made from what has been described without departure from the scope of the invention, it will be understood that I do not limit myself in these respects except as in the following claims.

I claim:

1. An artificial limb comprising a thigh portion and a shin portion articulated by means of a pivot bolt which is non-rotatable relative to the shin portion, a split brake drum fixed on said bolt, means fixed to the thigh portion and frictionally engaging said drum, and a lever for engagement by a control strap, said lever being formed with and projecting radially from one of the parts of said split drum.

2. An artificial limb comprising a thigh portion and a shin portionarticulated by means of a pivot bolt which is non-rotatable relative to the shin portion, a brake drum fixed on said bolt, a brake band anchored in said thigh portion and operatively engagingsaid drum, and a lever for engagement by a control strap, said lever being secured to said drum, the lever having parallel arms projecting substantially radially from said drum, the brake band being guided between the lever arms.

3. An artificial limb comprising a hollow shin portion and a bracket including a band portion secured to the upper margins of said shin portion throughout the circumferential extent of the latter, said bracket having integral bearing portions for a pivot bolt, a pivot bolt supportedin said bearing portions, a thigh portion pivoted on said bolt, the rear part of the band'portion being downwardly off-set relative to its forward portion and having a downwardly curved upper edge adapted to abut the rear surface of the thigh portion to limit relative bending in one direction of the two limb portions, said rear surface being transversely curved and the curve of said upper edge conforming substantially thereto to provide extended abutting contact, said thigh portion having a lower rear part extending in front of and abutting the rear part of said band portion when the two limb portions are in straightened relation.

4. An artificial leg comprising a thigh portion,

a hollow shin portion having a downwardly curved upper edge at its rear, a bracket secured to the shin portion and comprising a pair of spaced hearing portions adapted to receive a pivot bolt and a band portion joining said bearing portions, said band portion extending across the rear of said shin portion adjacent the upper edge of the shin portion and being arched downwardly between. the bearing portions and conforming substantially to the curvature of the upper edge of the shin porv tion adjacent the same, the thigh portion having at its lower end a rear wall extended downwardly below said bearing portions sufficiently to engage the front surface of said band portion when the thigh and shin portions are straightened whereby the band portion serves as a combined reinforce for the shin portion and as a stop for limiting relative movement between the same and the thigh portion, the downward arching of the band portion permitting the thigh portion to move through an angle greater than a right angle to the shin portion, the top of said band portion serving as a stop for limiting such angular movement.

the upper edge of said shin portion at its rear,

said band and bearing portions being integral, the rearwardly extending band portion being arched downwardly between the bearing portions whereby to conform substantially to the curvature of the upper edge of the shin portion, the thigh portion having at its lower 'end a rear wall extended downwardly below said bearing portions sufliciently to engage the front surface of said rearward band portion when the thigh and shin portions are straightened whereby the band portions serve as a combined reinforce for the shin portion and the rearward band portion serves as a stop for limiting straightening movement of the shin and thigh portions, the downward arching of the rearward band portion per-.

mitting the thigh portion to move through an angle greater than a right angle relative to the shin portion, the. top of said rearward band 1301'".

tion serving as a stop for limiting such angular movement.

enemas 11.1mm. 

